It takes a lot to cancel church in the shiny Bible Belt stronghold of Houston, Texas, home to more megachurches than any city in America. Specifically, 9 trillion gallons of rain in a weekend.

Hurricane Harvey shut down Sunday services from downtown to the sprawling suburbs, where churches replaced typical worship gatherings with sermon videos posted on Facebook or simply messages to stay safe.

Almost all Houston-area churches—including the Bayou City’s biggest congregations such as Second Baptist, Houston’s First Baptist, Church Without Walls, Wheeler Avenue Baptist, and Woodlands Church—canceled all Sunday activities as a precaution.

The congregations were glad they did when unprecedented rain levels ended up blocking many routes and leakinginto some church buildings by Saturday night and Sunday morning.

“We have five services on the weekend, and I cannot ever remember canceling all services,” said Chris Seay, lead pastor at Ecclesia. “We asked our community to stay home with family and to look out for their neighbors.”

Gregg Matte, pastor at Houston’s First Baptist, spent the weekend checking in with members of his congregation—from elderly evacuees to a local TV meteorologist—with whom he has been texting Bible verses in between broadcasts.

“I don’t know that I’ve ever prayed like that, like I prayed today, just asking God to have mercy on us,” Matte said in a Facebook video Sunday evening. “Just make the rain stop.”

Houston Christians did more than pray from the dry refuge of their homes or evacuation spots. Clergymen were featured in a couple viral news reports from Sunday: a preacher who checked submerged cars for trapped drivers, and a priest who tried to paddle his way to Mass at Houston’s Catholic Charismatic Center.

Several churches located on higher ground served as temporary shelters or meeting points for evacuees. Members with clear routes shuttled friends or dropped off supplies.

“Right now we are getting supplies together to take to a few area shelters. Baby stuff seems to be in short supply,” said Jason Crandall, pastor of CityView Church in Pearland, a southern suburb.

However, there’s only so much they can do right now, with many churches themselves affected and more rain on its way. For example, celebrity pastor Joel Osteen’s Lakewood Church, which meets in a 16,800-seat arena, cannot open its doors to house displaced families because the church itself is inaccessible due to the flooding.